This invention relates to fencing systems in general, and to flexible, plastic fence boards or slats for use in such systems in particular.
It is well known in the patent literature to provide flexible, plastic fencing. For example, in my own prior U.S. Pat. Nos. 4,465,263 and 4,684,107, I disclose flexible, plastic webbing, reinforced with synthetic or steel wires which provide high strength fencing, especially adapted for livestock enclosures. Flexible, plastic webs or slats for fence constructions are also disclosed in U.S. Pat. Nos. 4,124,198; 3,347,527; 3,426,536 and 4,339,114.
It is also known to use flexible, plastic sheet material in fence constructions, and reference is made to U.S. Pat. Nos. 3,111,303 and 2,997,277 for representative examples.
One desirable characteristic for flexible, plastic fencing material is the ability to be rolled up for storage and shipment, so as to conserve space and therefore reduce costs. As a result, the prior art flexible fencing material is substantially of two-dimensional construction, i.e., it has measurable length and height dimensions but has no appreciable thickness or depth dimension which would otherwise cause the construction to be too rigid for rolling. However, there is also much interest in providing flexible fencing material which simulates conventional wood boards or slats which are generally on the order of 3/4 of an inch thick or greater.
It is therefore the principal object of the present invention to provide a hollow, flexible, plastic fencing board material which can assume a first position where it has an appreciable thickness dimension so as to simulate a wooden board or slat, but which is collapsible to a substantially flattened configuration which permits rolling for storage and/or shipment.
In accordance with this invention, therefore, continuously extruded, hollow plastic material is produced having a generally rectangular configuration with well defined length, width and thickness dimensions. This fencing board material includes first and second face portions separated by upper and lower edge wall portions, thereby defining a hollow interior. In order to facilitate collapsing of the fence board material to a substantially flattened configuration, thinned regions extend along each of four intersections of the first and second face portions with the upper and lower edge wall portions, i.e., at and along the four corners of the rectangular construction. These thinned regions are formed by utilizing a suitably shaped core mandrel to cooperate with the interior surfaces of an extrusion die, so that the thinned region is not apparent from viewing the external surface of the plastic board. However, it will be appreciated that a core mandrel of rectangular cross section could be utilized in cooperation with an extrusion die which would be provided with suitable corner configurations to provide thinned areas externally visible at each of the four corner locations.
By providing thinned regions extending longitudinally along each of the corner intersections, the plastic fencing board or slat material of this invention is collapsible to a generally flattened condition wherein the upper and lower edge wall portions extend substantially parallel and coplanar with the first and second face portions. This configuration permits easy rolling of the material for shipment and/or storage.
Upon unrolling, desired lengths of material may be cut to form individual boards or slats. Thereafter, the boards or slats may be manually manipulated to the generally rectangular, hollow configuration, with the upper and lower edge wall portions extending substantially perpendicular to the first and second face portions, thereby providing a desirable degree of overall rigidity to the boards.
It is a feature of this invention that the plastic fence board or slat material may be attached to conventional fence posts of various shapes including square, rectangular or round with conventional brackets. Alternatively, the fencing board material of this invention may be utilized in conjunction with fence posts provided with holes (as in traditional split rail type fence configurations) where the elongated fence board material is inserted through the holes in the fence posts.
It is another feature of this invention to provide contraction/expansion joint members which are shortened, hollow, rectangular members of fairly rigid construction, and which have a cross sectional shape matching that of the fence board material in its expanded or installed configuration. The external dimensions of the expansion/contraction joint member are slightly less than the internal dimensions of the fence board material so that the joint members fit snugly within adjacent board ends. These members are designed to facilitate end-to-end attachment of two adjacent fence board members, to accommodate any expansion or contraction therebetween as a result of changes in temperature, for example, and to maintain the rectangular shape of the boards.
It is still another feature of this invention to provide a component similar to the expansion/contraction joint members, but wherein the internal dimension is matched to the external dimension of the fence board material so as to form an externally applied shape retaining sleeve. This is especially useful for very long sections of fence board where it is obviously desirable to insure that the hollow, rectangular shape of the fence board is maintained.
From the above, it will be appreciated that in one aspect, the present invention relates to a method of constructing a fence comprising the steps of (a) providing a roll of flexible fencing board material having a pair of opposed, elongated face portions and upper and lower edge walls in a substantially flattened configuration; (b) unrolling predetermined lengths of the fencing board material; (c) cutting the predetermined lengths of the fencing board material from the roll; (d) reforming the fencing board material to a substantially rectangular, hollow configuration; and (e) securing the predetermined lengths of fencing board material to at least a pair of spaced fence posts.
In another aspect, the invention relates to a fence board construction comprising a flexible length of plastic material having a pair of face surface portions separated by upper and lower edge wall portions, wherein thinned hinge regions are provided at each of four corners along respective intersections of the face surface portions and upper and lower edge wall portions to thereby permit the fence board to be collapsed to a substantially flattened configuration.
In still another aspect, the present invention relates to a roll of fence board material comprising an elongated length of flexible, plastic material in a substantially flattened configuration, and including four hinge areas, each extending in parallel along the length of the material, and located to permit reformation of the length upon unrolling to a hollow, rectangular configuration defined by a pair of face portions separated by upper and lower edge wall portions.
The invention also relates to a fencing system comprising a plurality of fence posts; a plurality of flexible fence boards, as described above, and a plurality of brackets and fasteners for securing the boards to the fence posts.
Other objects and advantages of the fence construction in accordance with this invention will become apparent from the detailed description of the invention in conjunction with the attached drawings.